ATI RN
microbiology an introduction tortora test bank Questions
Question 1 of 9
Which bacteria produce exotoxins that can cause severe dehydration and diarrhea?
Correct Answer: A
Rationale: The correct answer is A: Vibrio cholerae. This bacterium produces cholera toxin, an exotoxin that causes severe dehydration and diarrhea by increasing the secretion of electrolytes and water in the intestines. Vibrio cholerae is the causative agent of cholera, a disease characterized by profuse watery diarrhea. Choice B, Clostridium tetani, produces tetanospasmin causing tetanus, not dehydration or diarrhea. Choice C, Escherichia coli, can cause diarrhea but rarely severe dehydration. Choice D, Shigella dysenteriae, produces Shiga toxin leading to bloody diarrhea, not severe dehydration.
Question 2 of 9
Which bacteria is commonly associated with hospital-acquired infections?
Correct Answer: C
Rationale: The correct answer is C: Staphylococcus aureus. This bacterium is commonly associated with hospital-acquired infections due to its ability to cause a wide range of infections and its resistance to multiple antibiotics. Staphylococcus aureus can cause skin infections, pneumonia, bloodstream infections, and surgical site infections, making it a significant threat in healthcare settings. Escherichia coli (choice A) is more commonly associated with foodborne illnesses. Clostridium difficile (choice B) is known for causing antibiotic-associated diarrhea. Bacillus anthracis (choice D) is primarily associated with anthrax infections, which are not typically acquired in hospital settings.
Question 3 of 9
For serological diagnostics of the whooping cough it was made large-scale reaction with parapertussis and pertussis diagnosticums. At the bottom of the test-tubes with diagnosticum of Bordetella parapertussis grain-like sediment formed. What antibodies have this reaction revealed?
Correct Answer: B
Rationale: Rationale: 1. The grain-like sediment indicates a precipitation reaction. 2. Precipitins are antibodies that cause precipitation reactions. 3. In serological diagnostics, precipitation reactions are used to detect specific antibodies. 4. Therefore, the reaction revealed in this scenario is due to the presence of precipitins. Summary: A: Bacteriolysins - These antibodies cause bacterial lysis, not precipitation. C: Antitoxins - These antibodies neutralize toxins, not involved in precipitation reactions. D: Opsonins - These antibodies enhance phagocytosis, not related to precipitation reactions.
Question 4 of 9
All of the following are ways the kidney are used for urine formation and drug clearance except:
Correct Answer: C
Rationale: The correct answer is C: Tubular filtration. The kidney does not perform tubular filtration as a method for urine formation and drug clearance. The process of urine formation involves filtration, secretion, and reabsorption. Filtration occurs at the glomerulus, where blood is filtered to form the initial filtrate. Tubular secretion involves the active transport of substances from the blood into the renal tubules to be eliminated in urine. Tubular reabsorption is the process of reclaiming useful substances from the filtrate back into the blood. Therefore, tubular filtration is not a valid process in urine formation and drug clearance, making it the correct answer. Choices A, B, and D are incorrect as they are essential processes in urine formation and drug clearance.
Question 5 of 9
Which of the following pathogenic mechanisms are not typical for autoimmune reactions?
Correct Answer: D
Rationale: The correct answer is D, Formation of CD4+ cells. In autoimmune reactions, CD4+ cells are actually involved in the immune response. Here's the rationale: 1. CD4+ cells are helper T cells that play a crucial role in activating other immune cells in autoimmune reactions. 2. Decreased functional activity of T-suppressors (Choice A) is typical in autoimmune reactions as it leads to unchecked immune responses. 3. Loss of tolerance for T-helpers and B-lymphocytes (Choice B) is common in autoimmune reactions, where the immune system mistakenly attacks self-cells. 4. Ag released by normally isolated tissues (Choice C) is a typical mechanism in autoimmune reactions where self-antigens trigger immune responses.
Question 6 of 9
F pili:
Correct Answer: C
Rationale: The correct answer is C because F pili are proteins on the F+ donor cell that are attached to specific receptors on the recipient cell's cell wall. This is essential for the transfer of genetic material during conjugation. Choice A is incorrect because F pili are not made up of nucleotides, but rather proteins. Choice B is incorrect because F pili are not transferred to the recipient cell itself, but they facilitate the transfer of genetic material. Choice D is incorrect because F pili are not part of the recipient cell, but rather part of the donor cell for attachment to the recipient cell.
Question 7 of 9
The role of adhesins in gram positive bacteria is carried out by:
Correct Answer: A
Rationale: Adhesins in gram positive bacteria are typically carried out by surface structures such as lipoteichoic acids. These molecules help the bacteria adhere to host cells or tissues. Lipoteichoic acids are specific to gram positive bacteria and play a crucial role in initiating infections. Fimbriae, flagella, and short chain mycolic acids are not primarily responsible for adhesion in gram positive bacteria. Fimbriae are more commonly found in gram negative bacteria, flagella are involved in motility, and short chain mycolic acids are specific to mycobacteria. Therefore, the correct answer is A, lipoteichoic acids.
Question 8 of 9
A wound smear revealed Gram-negative rods producing blue-green pigment. The bacteria had a fruity odor. What is the causative agent?
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas aeruginosa. Pseudomonas aeruginosa is known to produce a blue-green pigment called pyocyanin, which is characteristic of the organism. Additionally, it has a distinct fruity odor due to the production of certain volatile compounds. Escherichia coli (B) does not produce blue-green pigment or have a fruity odor. Klebsiella pneumoniae (C) and Proteus mirabilis (D) also do not exhibit these specific characteristics associated with Pseudomonas aeruginosa.
Question 9 of 9
Which of the following characteristics does not refer to the flu vaccine
Correct Answer: D
Rationale: The correct answer is D because the flu vaccine primarily stimulates systemic immunity rather than local immunity. It is administered parenterally (C) as it is injected into the body. It is a subunit vaccine (B) as it contains only specific antigens of the virus. It is a recommended vaccine (A) due to its effectiveness in preventing influenza. In summary, D is the correct choice as the flu vaccine mainly targets systemic immunity, not local immunity, unlike the other characteristics listed.